It varies among the ~dozen of modems they've used, but they do have pppoe support; AT&T's GUI won't show it to you.

dot1x isn't "proprietary" -- they just aren't giving anyone else any keys. And you'd still need the serial number from one of their blessed devices to logon anyway.

The real issue with the PTM gear is the lack of any ATM mode, or access to enable it. The only one I suspect has (had?) full functionality is the horrible moto NVG. It's not uncommon to only include one mode in the firmware to save space (and maybe cost.)

they just aren't giving anyone else any keys. And you'd still need the serial number from one of their blessed devices to logon anyway.--.

This makes it proprietary

The real issue with the PTM gear is the lack of any ATM mode, or access to enable it. The only one I suspect has (had?) full functionality is the horrible moto NVG. It's not uncommon to only include one mode in the firmware to save space (and maybe cost.)